下面各题怎样简便就怎样算.5÷(7÷11)÷(11÷16)÷(16÷35)28.67×67+315×286.7+573.4×12010×

下面各题怎样简便就怎样算.5÷(7÷11)÷(11÷16)÷(16÷35)28.67×67+315×286.7+573.4×12010×(425+212)-1÷12.5% 1991+19911991+199119911991+…2002+20022002+200220022002+….

第1个回答  2014-09-28
(1)5÷(7÷11)÷(11÷16)÷(16÷35),
=5÷
7
11
÷
11
16
÷
16
35

=5×
11
7
×
16
11
×
35
16

=25;

(2)28.67×67+3
1
5
×286.7+573.4×
1
20

=28.67×67+3.2×286.7+573.4×0.05,
=28.67×67+32×28.67+28.67,
=(67+32+1)×28.67,
=100×28.67,
=2867;

(3)10×(4
2
5
+2
1
2
)-1÷12.5%,
=10×(4.4+2.5)-1÷
1
8

=10×6.9-1×
1
8

=69-8,
=61;

(4)
1991+19911991+199119911991+…
2002+20022002+200220022002+…

=
1991×(1+10001+100010001+…)
2002×(1+10001+100010001+…)

=
1991
2002
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